Furnace for the decomposition of alkali-metal chlorides



Patented Nov. 20, 1928.

UNITED STATES PATENT OFFICE.

JULIUS KEBSTEN, F BENSHEIM, GERMANY.

FUBNACE FOR THE DECIOLIPOSI'IION 0F ALKALI-METAL CHLORIDES..

- Application filed September 19, 1924, Serial No. 788,654, and in Germany October 6, 1923.

This invention has for its object an economical carrying out of the commonly known process of decomposition of alkali` metal chlorides by steam in which a molten mass of alkali metal chloride and of a s1l1 cate, as potassium silicate or sodium sillcate is prepared which contains the silicic acid Example; 2iac1+112o+Nico 2sio,=`

enciwmazoxsioz).

According to-the invention one proceeds in the following manner: To the molten mass of alkali metal chloride and silicate, carbon, for instance graphite or charcoal is added in solid form which ldissolves colloidally 1n the mass and, besides the steam, air is further injected into the mass whereby'in the 1nterioi' of the mass combustion of a portion of the carbon and consequently the complete transmission to the mass of the heat' produced is obtained, another ortion of the carbon serving to produce. y the decomosition of the steam the generation of free liydrogen. The process is in detail as foll0WS:- Y

1. 4NaCl -l- 2H2O 2Na20 -I-ftHCl.

The steam, superheated as muchas possible, is injected and the quantity of heat is generated by the' combustion of a part of the added carbon by the airV which is required to decompose the alkali metal chloride and to maintain the mass in the molten state during the decomposition, another portion of In this manner.

Vis horizontal and situate main process-in the desired manner with the` silicates to form the desired alkali metal i salt.

In certain cases the direct inner heatingI of the molten mass by means of air injected for combustion of the carbon may be dispensed with, an external heating of the converter or an intense heating, for instance gas heating, being employed. In this case the abovestated chemical action of the carbon takes' place also. f

For carrying fout the process according to the invention anv apparatus of the type shown by way of example on the accompanying drawing -is preferably used, gig. l illustrates in longitudinal vsection an Fig. 2 in cross section a` furnace working without interruption. f

The Yfurnace shown in thel drawing is constructed in suclia manner th t the initial substances are charged into t e same conbe exposed to decomposition. The liquid I product from decomposition flows out from this chamber automatically in accordance with the quantity of initial substances fed into the oven.

This furnace of very simple construction consists of a chamber z. similar to a shaft having a grate-like bottom plate c'gthe slits of which form injecting nozzles for steam and air. Below this bottom plate c boxes Z are arranged through which the steamand .06

l the air are conducted tothe nozzles either together or separately.

- In the end wall a of the :furnace a channel n, or several such channels, is arranged which is downwardly inclined and terminates in the chamber h. The molten material coming from the melting furnace is charged through this channel fn, continuously.. into the chamber 71,. In the opposite end wall o of the furnace a second channel (or several such channelsf is arran ed which on a hig er plane than the channel n. vThrough channel p the decomposed material Hows continuously out in a quantity which corresponds with the fresh charge fed into the chamber h through the channel n. The chamber h is thus constantly filled up to the height of channel p, As the inflow channely fn, is situated on a lower plane than the outflow chan; nel p the fresh molten material flows always into the substances contained in the chamber h.'

In the top plate g of the furnace outlet ports vare arranged through which the hydrochloric acid flows continuously' over into a collector s from which it can be withdrawn with the aid of any suitable means.

I claim: Y p

A furnace for the decomposition of alkali vmetal chlorides by steam in the presence of silicates in a molten mass, comprising in 4combination a shaftf. enclosed by masonry, a

grate like bottom plate in said shaft and having slits which form injecting nozzles, air boxes Iand steam boxes under said grate like bottom plate, means for connecting said boxes with said grate like bottom plate to supply air and steam to said slits, Aa'collector for the escaping gases at the top end of said shaft, a permanently open inlet channel for the supply of the molten mass at the one side of saidl shaft at about the middle height of' said shaft, andga permanently open outiiow channel at the other side of said shaft at ,the heightof the liquid level in said shaft and designed fordischarging the products from decomposition, a top plate on said shaft and having outlet ports, and a collector above said top plate designed to collect the hydrochloricacid which is generated so thatthe `initial materials with addition of carbon lare continuously charged into the furnace and the products from decomposition are continuously discharged from the same,

In testimony whereof I affix my signature.

DR. JULIUS KERSTEN. 

